|Related CVE||CVE-2019-0154 CVE-2019-11135|
Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service, or information leak.
Intel discovered that on their 8th and 9th generation GPUs, reading certain registers while the GPU is in a low-power state can cause a system hang. A local user permitted to use the GPU can use this for denial of service. This update mitigates the issue through changes to the i915 driver. The affected chips (gen8) are listed at <https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units#Gen8>;.
It was discovered that on Intel CPUs supporting transactional memory (TSX), a transaction that is going to be aborted may continue to execute speculatively, reading sensitive data from internal buffers and leaking it through dependent operations. Intel calls this "TSX Asynchronous Abort" (TAA). For CPUs affected by the previously published Microarchitectural Data Sampling (MDS) issues (CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091), the existing mitigation also mitigates this issue. For processors that are vulnerable to TAA but not MDS, this update disables TSX by default. This mitigation requires updated CPU microcode. An updated intel-microcode package (only available in Debian non-free) will be provided via a future ELA. The updated CPU microcode may also be available as part of a system firmware ("BIOS") update. Further information on the mitigation can be found at <https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html> or in the linux-doc-3.16 package. Intel's explanation of the issue can be found at <https://software.intel.com/security-software-guidance/insights/deep-dive-intel-transactional-synchronization-extensions-intel-tsx-asynchronous-abort>;.
For Debian 7 Wheezy, these problems have been fixed in version 3.16.76-1~deb7u1.
We recommend that you upgrade your linux packages.
Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/